X Membrane Transport2 Mfm Dcom Exam2

Front 1

in cellular ion gradients, which ion is the only one with higher concentrations inside the cell? (all the others have higher concentrations outside the cell)

Back 1

k⁺

Front 2

which side of a cell is typically more negative?

Back 2

the inside

Front 3

what does this describe:

spontaneous movement of molecules from areas of higher concentration to areas of lower concentration (“downhill”, movement along a concentration gradient)

Back 3

simple diffusion

Front 4

what are the molecules involved in simple diffusion:
1.
2.
3.
4.
5.
6.

Back 4

1. O2
2. CO2
3. H20
4. ethanol
5. steroid hormones
6. hydrophobic vitamins

Front 5

the following describes what:

transmembrane protein creates a water-filled pore through which ions and other small hydrophilic molecules can pass by diffusion

Back 5

facilitated diffusion

Front 6

in facilitated diffusion transmembrane proteins have channels that are regulated or ... to control amount of diffusion allowed across membrane

Back 6

“gated”

Front 7

the below describes what:

small signaling molecule (or ligand) binds to a channel, creating a conformational change that “opens” the channel

Back 7

ligand-gated ion channels

Front 8

... is an extracellular ligand that opens Na+ channels in neurons to initiate a nerve impulse

Back 8

Acetylcholine

Front 9

... is an extracellular ligand that opens Cl- channels to inhibit creation of a nerve impulse

Back 9

GABA

Front 10

examples of intracellular ligands are:
1.
2.
3.

Back 10

1. cAMP (olfaction)
2. cGMP (vision)
3. ATP opens Cl- and HCO3- channels

Front 11

stereocilia of hair cells in the cochlea get distorted or bent by sound waves which
opens Na+ channels to create nerve impulse that brain interprets as a sound

this is an example of ...

Back 11

mechanically-gated ion channels

Front 12

Stretch receptors in tendons and muscles are examples of ...

Back 12

mechanically-gated ion channels

Front 13

in ... some channels open in response to local changes in charge across the plasma membrane

2 types of cells that do this are:
1.
2.

Back 13

voltage-gated ion channels
muscle
neuron

Front 14

what kind of transport is this and what is happening with the transport protein?

Back 14

passive transport
conformational change

Front 15

... transport is against the concentration gradient and requires ...

Back 15

active
ATP

Front 16

what are the following:
Na+/K+ ATPase
H+/K+ ATPase
Ca2+ ATPase

Back 16

transmembrane transporters that possess ATPase activity

Front 17

... is found in almost every cell and uses ⅓ of the cell’s supply of ATP. it pumps out ... Na+ for every ... K+ it pumps in

Back 17

Na+/K+ ATPase
3
2

Front 18

why is Na+/K+ ATPase important?
1.
2.
3.

Back 18

1. establishes a net charge across the plasma membrane called
2. helps to maintain osmotic balance
3. gradient of Na+ ions harnessed to provide energy to drive several secondary active transporters

Front 19

the interior of the cell being more negatively charged with respect to the exterior is known as ...

Back 19

resting membrane potential

Front 20

... uses the downhill flow of one ion to pump some other molecule or ion against its concentration gradient
driving ion is usually ...

the pumped molecule can move in same direction ... as ... or opposite direction ... as ...

Back 20

coupled or secondary active transport
Na+
symport
Na+
antiport
Na+

Front 21

where would you find Na+/glucose transporter (a symport) and why?

Back 21

in intestinal epithelium and kidney tubules ensures glucose is transported back into the bloodstream

Front 22

where would you find amino acid symporters.

Back 22

kidneys and in synaptic clefts

Front 23

special term used to describe the diffusion of water through a cell membrane is known as ...

Back 23

osmosis

Front 24

osmosis can include facilitated diffusion through water channels called ...

Back 24

aquaporins

Front 25

... solutions have a concentration of water that is greater outside the cell due to lower solute concentration

Back 25

Hypotonic

Front 26

... solutions have a concentration of water that is lower outside the cell due to higher solute concentration

Back 26

Hypertonic

Front 27

... solutions are where concentration of water and total solute are equal inside and outside the cell

Back 27

Isotonic

Front 28

when a cell shrinks and shrivels it is called ...

Back 28

crenation

Front 29

cystic fibrosis is a ... channel disease where there is a mutation in ... that results in defective ... ion transport

Back 29

Chloride
CFTR gene (cystic fibrosis transmembrane conductance regulator)
Cl-

Front 30

CF is the most common lethal inherited disease of ... (1 in 2500) where the average life expectancy is 37 years.
lung disease responsible for ... of mortality and the
incidence of heterozygous carriers: 1 in ...

Back 30

Caucasians
95%
25